Toyota’s VVT-I (Variable Valve Timing Intelligence) is the company’s name for the variable valve technology it uses in most of its vehicles.
Toyota says that by optimizing valve timing based on driving conditions, VVT-I increases power, improves fuel economy and reduces emissions.
Alfa Romeo was the first automobile manufacturer to offer variable valve timing in 1980. Then Honda with VTEC in 1989.
Followed by Toyota in 1995 featured in the Toyota Supra and Lexus SC 300 which didn’t come to the U.S. market until mid-1997 for the 1998 model year.
Take a ride with us we learn more about Toyota’s VVT-I.
What Does VVT-I Do?
Though the details differ depending on manufacturer, the system makes small adjustments to when the engine intake valves open and close to feed the proper air-fuel mixture into the engines based on how you’re driving.
The result is maximized performance and reduced emissions. Toyota’s VVT-I is an electronic control unit responsible for managing engine operations by continuously calculating the best time to open and close the valves.
It activates an oil pressure valve to change the timing by altering camshaft speed.
Horsepower Figures for Toyota’s Most Popular Engines with VVT-I
The most famous Toyota engine supported by the company’s VVT-I technology is the 3.0-liter 2JZ.
It’s a 24-valve V6 motor you can find in the Supra and Lexus SC300 where its capable of making 212-227 horsepower at 5800 to 6000 RPM.
Toyota’s 2AZ-FE is a popular 2.4-liter inline four which can be found in everything from a Camry to a Scion TC.
It’s a 16-valve DOHC engine with a 145 HP at 6000 RPM. The 2ZZ engine is just about as ubiquitous.
Providing a bit more oomph, you can find it most obviously in the Celica GT-S from 2000-2005 and powering cars even like the Lotus Elise and Exige S.
While it has a modest horsepower of 109 at 6000 RPM.
Designed by Yamaha, the 1.8-liter inline four 2ZZ-GE uses Toyota’s VVTL-I valvetrain to compete against Honda’s VTEC system to produce a maximum of 182 HP at 7600 RPM.
Disadvantages of the VVT-I Motor
After multi-valve technology became a standard feature of engine design, Variable Valve Timing was the next step.
But while VVT-I does a herculean job of bridging performance with efficiency. Like all things man made, it’s not without its issues.
A major issue with these Toyota’s VVT-I engines is oil consumption. It’s typically related to faulty pistons and piston rings.
This is often accompanied by excessive exhaust smoke, poor acceleration and diminished vehicle performance.
And the Toyota cars most effected by oil consumption are the Corollas starting from early 2000.
Specifically, Corollas with the 2AZ engine like the XRS. To address this, Toyota launched the Warranty Enhancement Program ZE7.
Is a VVT Engine Good?
Think of an engine as a mechanical respiratory system. What VVT-I technology does is improve engine efficiency.
Thereby increasing the engine’s ability to process air. The net result of which is increased horsepower.
There are a number of ways to do this. But since engine valves play a major role in how air gets in and out of the combustion chamber.
Toyota’s genius lies in their focus on valve timing which increases power and efficiency without increasing fuel economy.
By varying the timing in which vales open and close according to the operating conditions of the car, the VVT-I engine improves performance and fuel efficiency.
The 1.6-liter VVT-I engine is well-known and refined featured most prominently in the Toyota Corollas.
Are Toyota’s Dual VVT-I Engines Good?
Well, you tell me. Are Toyota’s Camrys good?
These sedans make use of a 2.5-liter and 3.5-liter engine where the exhaust valves are enhanced with a type of variable timing called Dual VVT-I.
What this system does is adjust both the intake and exhaust valves, making it more efficient and reducing more emissions than VVT-I alone.
And of course, since one of the things VVT-I does is work to increase horsepower.
Dual VVT-I gives you even more power; better responsiveness; better fuel mileage as well as lower emissions.
Is VVT Better Than VTEC?
Now comes time to address the elephant in the room: is Toyota’s VVT-I better than Honda’s VTEC?
Developed by Ikuo Kajitani, VTEC is distinct from standard VVT. VVT-I systems only change the valve timings without changing the camshaft profile or valve lift.
To the chagrin of all the Toyota fanboys and girls, Honda’s I-VTEC is more potent than Toyota’s VVTI.
Not only is it more powerful at higher RPMs. But it comes close to being just as economical as VVT-I at low RPMs.
Although Toyota’s 2ZZ-GE is capable of high revving, it doesn’t get the same aftermarket support that Honda’s engines get.
That’s why fifth gen Celica owners in the know opt to swap in Honda’s KA20 motor.
How Long Can a VVT-I Engine Last?
Let’s take the 4.0-liter V6 Dual VVT-I engine featured in more than nine Toyota cars for example. It’s smooth and it’s quiet.
And if it’s well taken care of with regular scheduled maintenance it can easily reach over 200,000 miles (320,000 km).
Even Toyota forums confirm that the secret to VVT-I engine longevity lies in your ability to maintain them.
Is VVT the Same as CVT?
One system has to do with engines, the other with transmissions. So, no. VVT and CVT are not the same system at all.
But they are interrelated. The CVT (Continuous Variable Transmission) is used on engines that can change (or vary) their lift timing at high speeds.
Not just Toyota, but many new commuter cars and crossovers make use of a CVT.
It’s a type of automatic transmission that seamlessly shifts through gear ratios to help the engine run more efficiently.
You may hear them also referred to as shiftless transmissions.
Can You Turn Off VVT?
Do you mean, is there a button you can hit to toggle VVT technology on and off?
But let’s suppose you’re making upgrades to a Toyota engine with variable valve timing to increase performance.
You would need to remove the VVT system if you’re swapping to a non-VVT camshaft.
Ask any tuner and they’ll tell you that if you don’t do this right, you’ll risk blowing up your engine.
Turning you from a hero to a zero just as fast.
And that’s because the manufacturer of these VVT engines has put a lot of effort into adjusting for the best compromise between economy, emissions and power output.
A VVT delete kit helps you remove the VVT components to replace them with standard parts.